Hard Starting Randomly

[wessie]

I remember this being a problem that confused Yamaha with early Super Tenere bikes - similar symptoms in that the bike was hard to start when warm. I don't think anybody worked out why it happened. I had it once in the 3 years I owned the Super Ten. What people learnt was to open the throttle to fully open and just keep cranking the engine. Eventually the bike fired after a bit of coughing & spluttering and some smoke. As far as I know, nobody who experienced this had any long term problem with the bike - it may be that Yamaha tweaked the engine software which was updated during a service without making any publicity about it.
 
If anyone wants to read about the topic then do a google search of "Super Tenere hard start problem" as there is plenty of information on forums out there.

[fastfred]

I've had this problem with my bike many times. I have found that rolling the throttle back to remove all the cable slack and then slightly turning the throttle ever so slighty as pushing the starter button works for Me.

[skipperT]

I've had this problem with my bike many times. I have found that rolling the throttle back to remove all the cable slack and then slightly turning the throttle ever so slighty as pushing the starter button works for Me.

 
 
.... Which might mean that your TPS is out of adjustment as well. The Throttle Position Sensor angle is used by the ECU to determine when and how much fuel to inject. By rotating the throttle "ever so slightly" you are "showing" the ECU a different TPS voltage which changes how much gas the engine receives when cranking over.
 
I'd mention this to your dealer so they can check it. However it might be better to simply tell them what you are doing to help the bike start. The FJ 09 is a fly-by-Wire design that actually has 2 TPS sensors: one that is on the throttle body and one which is on the throttle Grip (called an APS or accelerator position sensor). they will need to figure out if either of them are slightly out of spec.
 
As a rule of thumb, you should NEVER have to touch the throttle when starting a FI machine. Be it bike, atv, car, etc. it usually confuses the ECU and makes it harder to get started.
 
HTH, Skip

[wessie]

Fly by wife?
 
No wonder some have trouble whilst others are trouble free.
 
 

[skipperT]

Fly by wife? 
No wonder some have trouble whilst others are trouble free.
 

 
 
Yeah, sorry. Was just trying to edit that. Hard on a mobile device.
Should read "Fly-by-wire"
 
Although the typo brings up interesting possibilities.

[woozer]

When I brought mine in for service, they asked me unprompted if I'd noticed this. It's done it a few times. Sometimes warm, sometimes cold. No pattern. I do agree that turning the ignition on and waiting until the fuel pump stops priming is a good idea.

[papac2000]

It would be interesting to know how many who have had this issue are from CA. Apparently FZ owners in California have remedied this issue by bypassing the evap canister specific to their emissions config.

[cthruu]

Mine does this and I'm from Cali. 

[ULEWZ]

Mine does this and I'm from Cali. 

I hit the starter right after the fuel pump is done priming and haven't had a problem since (only happened once). Maybe I was/am just lucky? 

[wessie]

It's part of the Californian directive to reduce emissions. They insist manufacturers stop you riding on one in 5 rides. In the course of the bike's lifetime this will cut emissions by 20%. It's not every 5th time, but averages out to 1 in 5. That's what happens when you let your state be ruled by people who have been using pot since the 1960s...

[ULEWZ]

It's part of the Californian directive to reduce emissions. They insist manufacturers stop you riding on one in 5 rides. In the course of the bike's lifetime this will cut emissions by 20%. It's not every 5th time, but averages out to 1 in 5. That's what happens when you let your state be ruled by people who have been using pot since the 1960s...

Boy, you nailed that one. Spot on. We have great weather, but...... :'( 

[pont]

I'm starting to wonder if this bike has less-than-perfect sensitivity at very low throttle. On STD or A throttle setting, it's very difficult to ride smoothly at low throttle. If the low throttle position is not accurate, then that could also explain the hard start due to throttle position sensor.

[wessie]

I'm starting to wonder if this bike has less-than-perfect sensitivity at very low throttle. On STD or A throttle setting, it's very difficult to ride smoothly at low throttle. If the low throttle position is not accurate, then that could also explain the hard start due to throttle position sensor.

A lot depends what you have been used too but I don't see this as a problem. Try riding an early Super Tenere with the factory ECU setting and you will experience a lack of smoothness. 
If you haven't had a 600 miles service yet then make sure your dealer does the throttle body balance that is specified in the service manual. Some dealers are skipping this as it adds time to the service as you need to lift the tank to access the vacuum take offs. The actual process is quite simple if you have a suitable electronic or mercury vacuum gauge as you just twiddle two screws on cylinders 2 and 3 to balance them to the same as 1 - the time is stripping the bike and putting it back together. 
 
It's a shame Yamaha didn't attach some rubber tubes to the vacuum spigots so you could take a reading with a mercury gauge without stripping the bike. This way you could check your throttle bodies are in spec and not bother to strip the tank etc if they are okay. This could save workshop time at the minor service times as if the throttle bodies stay in sync you would not need to take the tank off as plugs and air filters are not changed at every 6000 mile[0] service (air filter is a 24,000 mile job, plugs 12k and valves 24K if you go by the Yamaha spec[1])
 
[0] or 4000 miles if you live in N America I believe No I don't understand why oil lasts longer in Europe than N. America either, apart from you buy stuff cheaper than us in the first place so Yamaha has to fleece you in other ways.
[1] I am aware that some will say change the oil every other Tuesday and air filter with the phases of the moon but I go with the maker's advice. Start another thread if you want to argue about it. 

[thruster8999]

I'm starting to wonder if this bike has less-than-perfect sensitivity at very low throttle. On STD or A throttle setting, it's very difficult to ride smoothly at low throttle. If the low throttle position is not accurate, then that could also explain the hard start due to throttle position sensor.

A lot depends what you have been used too but I don't see this as a problem. Try riding an early Super Tenere with the factory ECU setting and you will experience a lack of smoothness. 
If you haven't had a 600 miles service yet then make sure your dealer does the throttle body balance that is specified in the service manual. Some dealers are skipping this as it adds time to the service as you need to lift the tank to access the vacuum take offs. The actual process is quite simple if you have a suitable electronic or mercury vacuum gauge as you just twiddle two screws on cylinders 2 and 3 to balance them to the same as 1 - the time is stripping the bike and putting it back together. 
 
It's a shame Yamaha didn't attach some rubber tubes to the vacuum spigots so you could take a reading with a mercury gauge without stripping the bike. This way you could check your throttle bodies are in spec and not bother to strip the tank etc if they are okay. This could save workshop time at the minor service times as if the throttle bodies stay in sync you would not need to take the tank off as plugs and air filters are not changed at every 6000 mile[0] service (air filter is a 24,000 mile job, plugs 12k and valves 24K if you go by the Yamaha spec[1])
 
[0] or 4000 miles if you live in N America I believe No I don't understand why oil lasts longer in Europe than N. America either, apart from you buy stuff cheaper than us in the first place so Yamaha has to fleece you in other ways.
[1] I am aware that some will say change the oil every other Tuesday and air filter with the phases of the moon but I go with the maker's advice. Start another thread if you want to argue about it. 

 
 
So do you think syncing the throttle bodies will smooth out the low end?
I can do my own 600 mile service except the throttle bodies.

[jimf]

It's a shame Yamaha didn't attach some rubber tubes to the vacuum spigots so you could take a reading with a mercury gauge without stripping the bike. This way you could check your throttle bodies are in spec and not bother to strip the tank etc if they are okay. This could save workshop time at the minor service times as if the throttle bodies stay in sync you would not need to take the tank off as plugs and air filters are not changed at every 6000 mile[0] service (air filter is a 24,000 mile job, plugs 12k and valves 24K if you go by the Yamaha spec[1])
 
[0] or 4000 miles if you live in N America I believe No I don't understand why oil lasts longer in Europe than N. America either, apart from you buy stuff cheaper than us in the first place so Yamaha has to fleece you in other ways.
 

Is there any particular reason you couldn't add those tubes yourself?  Keep in mind I'm something of a simpleton in many aspects of engine maintenance.  I've rebuilt a couple carbs, so I'm not entirely unfamiliar with the concept, but my mental model says that you could do this easily.  Am I wrong? 
Regarding the service length differences, could it be an oil difference?  Maybe dino versus synth?  That's approximately the difference I would expect if that were the case.  I'm not sure why they would use different oil in different markets, but maybe dino is substantially cheaper in the US, or there are differences in modifiers.
 
I would tend to change my oil by around 4500mi anyway if it's synthetic, if only because that's a springtime activity and historically I've done about that many miles a year.  (That is likely to go up with the FJ. :-)  So, I am unlikely to care even if Yamaha is doing it as a psychological play for stupid Americans who regularly run way past recommended service intervals.